Elastomeric polymers, both homopolymers and copolymers, are well known in the art and include natural rubber and a wide variety of synthetic elastomeric materials. One class of synthetic elastomeric polymers includes homopolymers such as polybutadiene, polyisoprene and chloroprene. A second class of such elastomeric copolymers which is common in the art and in commerce is referred to as ethylene-propylene-diene monomer elastomers (EPDM). These EPDM elastomers are particularly useful elastomers since they are produced from relatively low cost materials and have good mechanical and elastomeric properties as well as resistance to thermal and chemical degradation. Yet another class of particularly useful elastomeric copolymers is the class of thermoplastic elastomers which demonstrate elastomeric properties at ambient temperatures but which are processable by methods conventional for non-elastomeric thermoplastics at somewhat elevated temperatures. Such thermoplastic elastomers are illustrated by block copolymers of a vinyl aromatic compound and a conjugated alkadiene, for example, a block copolymer of styrene and butadiene. The properties of such block copolymers are improved for many applications by the hydrogenation of some or all of the unsaturation in the polyalkadiene or aliphatic portion and, on occasion, the poly(vinyl aromatic compound) or aromatic portion.
It is known that the properties of many elastomeric polymers are often modified by "curing" or cross-linking the polymer, typically by adding a cross-linking or curing agent and maintaining the resulting mixture at an elevated temperature. Cross-linking of natural rubber by heating with sulfur or a sulfur-containing compound is the commercial vulcanization needed to make the rubber suitable for many commercial applications. Other types of curing are available, as by heating with peroxides, for example. These methods often have disadvantages such as a slow curing rate which requires additional materials to accelerate or promote the curing rate to a commercially acceptable level, the presence of undesirable side reactions caused by the presence of free radicals generated by the curing process, or the release of volatile side products during curing. It would be of advantage to provide heat-curable elastomeric polymers, that is, functionalized elastomeric polymers which are curable at acceptable rate without the emission of volatiles and without the requirement for added curing agents and accelerators.